![Hagen Paul Pfeifer](/assets/img/avatar_default.png)
This adds an additional queuing strategy, called pfifo_head_drop, to remove the oldest skb in the case of an overflow within the queue - the head element - instead of the last skb (tail). To remove the oldest skb in congested situations is useful for sensor network environments where newer packets reflect the superior information. Reviewed-by: Florian Westphal <fw@strlen.de> Acked-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
587 lines
14 KiB
C
587 lines
14 KiB
C
#ifndef __NET_SCHED_GENERIC_H
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#define __NET_SCHED_GENERIC_H
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#include <linux/netdevice.h>
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#include <linux/types.h>
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#include <linux/rcupdate.h>
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#include <linux/module.h>
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#include <linux/pkt_sched.h>
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#include <linux/pkt_cls.h>
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#include <net/gen_stats.h>
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#include <net/rtnetlink.h>
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struct Qdisc_ops;
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struct qdisc_walker;
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struct tcf_walker;
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struct module;
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struct qdisc_rate_table {
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struct tc_ratespec rate;
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u32 data[256];
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struct qdisc_rate_table *next;
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int refcnt;
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};
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enum qdisc_state_t {
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__QDISC_STATE_RUNNING,
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__QDISC_STATE_SCHED,
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__QDISC_STATE_DEACTIVATED,
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};
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struct qdisc_size_table {
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struct list_head list;
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struct tc_sizespec szopts;
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int refcnt;
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u16 data[];
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};
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struct Qdisc {
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int (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
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struct sk_buff * (*dequeue)(struct Qdisc *dev);
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unsigned flags;
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#define TCQ_F_BUILTIN 1
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#define TCQ_F_THROTTLED 2
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#define TCQ_F_INGRESS 4
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#define TCQ_F_CAN_BYPASS 8
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#define TCQ_F_MQROOT 16
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#define TCQ_F_WARN_NONWC (1 << 16)
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int padded;
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struct Qdisc_ops *ops;
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struct qdisc_size_table *stab;
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struct list_head list;
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u32 handle;
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u32 parent;
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atomic_t refcnt;
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struct gnet_stats_rate_est rate_est;
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int (*reshape_fail)(struct sk_buff *skb,
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struct Qdisc *q);
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void *u32_node;
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/* This field is deprecated, but it is still used by CBQ
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* and it will live until better solution will be invented.
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*/
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struct Qdisc *__parent;
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struct netdev_queue *dev_queue;
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struct Qdisc *next_sched;
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struct sk_buff *gso_skb;
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/*
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* For performance sake on SMP, we put highly modified fields at the end
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*/
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unsigned long state;
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struct sk_buff_head q;
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struct gnet_stats_basic_packed bstats;
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struct gnet_stats_queue qstats;
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};
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struct Qdisc_class_ops {
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/* Child qdisc manipulation */
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struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *);
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int (*graft)(struct Qdisc *, unsigned long cl,
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struct Qdisc *, struct Qdisc **);
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struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl);
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void (*qlen_notify)(struct Qdisc *, unsigned long);
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/* Class manipulation routines */
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unsigned long (*get)(struct Qdisc *, u32 classid);
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void (*put)(struct Qdisc *, unsigned long);
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int (*change)(struct Qdisc *, u32, u32,
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struct nlattr **, unsigned long *);
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int (*delete)(struct Qdisc *, unsigned long);
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void (*walk)(struct Qdisc *, struct qdisc_walker * arg);
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/* Filter manipulation */
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struct tcf_proto ** (*tcf_chain)(struct Qdisc *, unsigned long);
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unsigned long (*bind_tcf)(struct Qdisc *, unsigned long,
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u32 classid);
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void (*unbind_tcf)(struct Qdisc *, unsigned long);
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/* rtnetlink specific */
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int (*dump)(struct Qdisc *, unsigned long,
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struct sk_buff *skb, struct tcmsg*);
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int (*dump_stats)(struct Qdisc *, unsigned long,
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struct gnet_dump *);
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};
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struct Qdisc_ops {
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struct Qdisc_ops *next;
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const struct Qdisc_class_ops *cl_ops;
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char id[IFNAMSIZ];
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int priv_size;
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int (*enqueue)(struct sk_buff *, struct Qdisc *);
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struct sk_buff * (*dequeue)(struct Qdisc *);
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struct sk_buff * (*peek)(struct Qdisc *);
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unsigned int (*drop)(struct Qdisc *);
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int (*init)(struct Qdisc *, struct nlattr *arg);
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void (*reset)(struct Qdisc *);
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void (*destroy)(struct Qdisc *);
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int (*change)(struct Qdisc *, struct nlattr *arg);
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void (*attach)(struct Qdisc *);
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int (*dump)(struct Qdisc *, struct sk_buff *);
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int (*dump_stats)(struct Qdisc *, struct gnet_dump *);
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struct module *owner;
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};
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struct tcf_result {
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unsigned long class;
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u32 classid;
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};
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struct tcf_proto_ops {
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struct tcf_proto_ops *next;
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char kind[IFNAMSIZ];
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int (*classify)(struct sk_buff*, struct tcf_proto*,
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struct tcf_result *);
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int (*init)(struct tcf_proto*);
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void (*destroy)(struct tcf_proto*);
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unsigned long (*get)(struct tcf_proto*, u32 handle);
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void (*put)(struct tcf_proto*, unsigned long);
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int (*change)(struct tcf_proto*, unsigned long,
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u32 handle, struct nlattr **,
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unsigned long *);
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int (*delete)(struct tcf_proto*, unsigned long);
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void (*walk)(struct tcf_proto*, struct tcf_walker *arg);
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/* rtnetlink specific */
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int (*dump)(struct tcf_proto*, unsigned long,
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struct sk_buff *skb, struct tcmsg*);
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struct module *owner;
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};
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struct tcf_proto {
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/* Fast access part */
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struct tcf_proto *next;
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void *root;
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int (*classify)(struct sk_buff*, struct tcf_proto*,
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struct tcf_result *);
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__be16 protocol;
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/* All the rest */
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u32 prio;
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u32 classid;
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struct Qdisc *q;
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void *data;
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struct tcf_proto_ops *ops;
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};
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struct qdisc_skb_cb {
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unsigned int pkt_len;
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char data[];
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};
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static inline int qdisc_qlen(struct Qdisc *q)
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{
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return q->q.qlen;
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}
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static inline struct qdisc_skb_cb *qdisc_skb_cb(struct sk_buff *skb)
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{
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return (struct qdisc_skb_cb *)skb->cb;
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}
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static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
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{
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return &qdisc->q.lock;
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}
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static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)
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{
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return qdisc->dev_queue->qdisc;
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}
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static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
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{
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return qdisc->dev_queue->qdisc_sleeping;
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}
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/* The qdisc root lock is a mechanism by which to top level
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* of a qdisc tree can be locked from any qdisc node in the
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* forest. This allows changing the configuration of some
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* aspect of the qdisc tree while blocking out asynchronous
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* qdisc access in the packet processing paths.
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*
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* It is only legal to do this when the root will not change
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* on us. Otherwise we'll potentially lock the wrong qdisc
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* root. This is enforced by holding the RTNL semaphore, which
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* all users of this lock accessor must do.
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*/
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static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
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{
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struct Qdisc *root = qdisc_root(qdisc);
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ASSERT_RTNL();
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return qdisc_lock(root);
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}
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static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
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{
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struct Qdisc *root = qdisc_root_sleeping(qdisc);
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ASSERT_RTNL();
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return qdisc_lock(root);
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}
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static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
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{
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return qdisc->dev_queue->dev;
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}
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static inline void sch_tree_lock(struct Qdisc *q)
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{
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spin_lock_bh(qdisc_root_sleeping_lock(q));
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}
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static inline void sch_tree_unlock(struct Qdisc *q)
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{
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spin_unlock_bh(qdisc_root_sleeping_lock(q));
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}
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#define tcf_tree_lock(tp) sch_tree_lock((tp)->q)
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#define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q)
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extern struct Qdisc noop_qdisc;
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extern struct Qdisc_ops noop_qdisc_ops;
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extern struct Qdisc_ops pfifo_fast_ops;
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extern struct Qdisc_ops mq_qdisc_ops;
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struct Qdisc_class_common {
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u32 classid;
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struct hlist_node hnode;
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};
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struct Qdisc_class_hash {
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struct hlist_head *hash;
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unsigned int hashsize;
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unsigned int hashmask;
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unsigned int hashelems;
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};
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static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
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{
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id ^= id >> 8;
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id ^= id >> 4;
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return id & mask;
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}
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static inline struct Qdisc_class_common *
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qdisc_class_find(struct Qdisc_class_hash *hash, u32 id)
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{
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struct Qdisc_class_common *cl;
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struct hlist_node *n;
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unsigned int h;
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h = qdisc_class_hash(id, hash->hashmask);
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hlist_for_each_entry(cl, n, &hash->hash[h], hnode) {
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if (cl->classid == id)
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return cl;
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}
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return NULL;
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}
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extern int qdisc_class_hash_init(struct Qdisc_class_hash *);
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extern void qdisc_class_hash_insert(struct Qdisc_class_hash *, struct Qdisc_class_common *);
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extern void qdisc_class_hash_remove(struct Qdisc_class_hash *, struct Qdisc_class_common *);
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extern void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
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extern void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
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extern void dev_init_scheduler(struct net_device *dev);
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extern void dev_shutdown(struct net_device *dev);
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extern void dev_activate(struct net_device *dev);
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extern void dev_deactivate(struct net_device *dev);
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extern struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
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struct Qdisc *qdisc);
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extern void qdisc_reset(struct Qdisc *qdisc);
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extern void qdisc_destroy(struct Qdisc *qdisc);
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extern void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
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extern struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
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struct Qdisc_ops *ops);
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extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
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struct netdev_queue *dev_queue,
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struct Qdisc_ops *ops, u32 parentid);
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extern void qdisc_calculate_pkt_len(struct sk_buff *skb,
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struct qdisc_size_table *stab);
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extern void tcf_destroy(struct tcf_proto *tp);
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extern void tcf_destroy_chain(struct tcf_proto **fl);
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/* Reset all TX qdiscs of a device. */
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static inline void qdisc_reset_all_tx(struct net_device *dev)
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{
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unsigned int i;
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for (i = 0; i < dev->num_tx_queues; i++)
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qdisc_reset(netdev_get_tx_queue(dev, i)->qdisc);
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}
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/* Are all TX queues of the device empty? */
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static inline bool qdisc_all_tx_empty(const struct net_device *dev)
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{
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unsigned int i;
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for (i = 0; i < dev->num_tx_queues; i++) {
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struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
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const struct Qdisc *q = txq->qdisc;
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if (q->q.qlen)
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return false;
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}
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return true;
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}
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/* Are any of the TX qdiscs changing? */
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static inline bool qdisc_tx_changing(struct net_device *dev)
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{
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unsigned int i;
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for (i = 0; i < dev->num_tx_queues; i++) {
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struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
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if (txq->qdisc != txq->qdisc_sleeping)
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return true;
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}
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return false;
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}
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/* Is the device using the noop qdisc on all queues? */
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static inline bool qdisc_tx_is_noop(const struct net_device *dev)
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{
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unsigned int i;
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for (i = 0; i < dev->num_tx_queues; i++) {
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struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
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if (txq->qdisc != &noop_qdisc)
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return false;
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}
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return true;
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}
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static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
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{
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return qdisc_skb_cb(skb)->pkt_len;
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}
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/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
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enum net_xmit_qdisc_t {
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__NET_XMIT_STOLEN = 0x00010000,
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__NET_XMIT_BYPASS = 0x00020000,
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};
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#ifdef CONFIG_NET_CLS_ACT
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#define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1)
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#else
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#define net_xmit_drop_count(e) (1)
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#endif
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static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
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{
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#ifdef CONFIG_NET_SCHED
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if (sch->stab)
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qdisc_calculate_pkt_len(skb, sch->stab);
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#endif
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return sch->enqueue(skb, sch);
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}
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static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
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{
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qdisc_skb_cb(skb)->pkt_len = skb->len;
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return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
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}
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static inline void __qdisc_update_bstats(struct Qdisc *sch, unsigned int len)
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{
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sch->bstats.bytes += len;
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sch->bstats.packets++;
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}
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static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
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struct sk_buff_head *list)
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{
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__skb_queue_tail(list, skb);
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sch->qstats.backlog += qdisc_pkt_len(skb);
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__qdisc_update_bstats(sch, qdisc_pkt_len(skb));
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return NET_XMIT_SUCCESS;
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}
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static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
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{
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return __qdisc_enqueue_tail(skb, sch, &sch->q);
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}
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static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
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struct sk_buff_head *list)
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{
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struct sk_buff *skb = __skb_dequeue(list);
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if (likely(skb != NULL))
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sch->qstats.backlog -= qdisc_pkt_len(skb);
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return skb;
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}
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static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
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{
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return __qdisc_dequeue_head(sch, &sch->q);
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}
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static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
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struct sk_buff_head *list)
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{
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struct sk_buff *skb = __qdisc_dequeue_head(sch, list);
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if (likely(skb != NULL)) {
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unsigned int len = qdisc_pkt_len(skb);
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kfree_skb(skb);
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return len;
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}
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return 0;
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}
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static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
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{
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return __qdisc_queue_drop_head(sch, &sch->q);
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}
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static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
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struct sk_buff_head *list)
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{
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struct sk_buff *skb = __skb_dequeue_tail(list);
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if (likely(skb != NULL))
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sch->qstats.backlog -= qdisc_pkt_len(skb);
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return skb;
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}
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static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
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{
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return __qdisc_dequeue_tail(sch, &sch->q);
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}
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static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
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{
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return skb_peek(&sch->q);
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}
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/* generic pseudo peek method for non-work-conserving qdisc */
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static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
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{
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/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
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if (!sch->gso_skb) {
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sch->gso_skb = sch->dequeue(sch);
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if (sch->gso_skb)
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/* it's still part of the queue */
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sch->q.qlen++;
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}
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return sch->gso_skb;
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}
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/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
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static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
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{
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struct sk_buff *skb = sch->gso_skb;
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if (skb) {
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sch->gso_skb = NULL;
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sch->q.qlen--;
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} else {
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skb = sch->dequeue(sch);
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}
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return skb;
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}
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static inline void __qdisc_reset_queue(struct Qdisc *sch,
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struct sk_buff_head *list)
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{
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/*
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* We do not know the backlog in bytes of this list, it
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* is up to the caller to correct it
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*/
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__skb_queue_purge(list);
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}
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static inline void qdisc_reset_queue(struct Qdisc *sch)
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{
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__qdisc_reset_queue(sch, &sch->q);
|
|
sch->qstats.backlog = 0;
|
|
}
|
|
|
|
static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
|
|
struct sk_buff_head *list)
|
|
{
|
|
struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
|
|
|
|
if (likely(skb != NULL)) {
|
|
unsigned int len = qdisc_pkt_len(skb);
|
|
kfree_skb(skb);
|
|
return len;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
|
|
{
|
|
return __qdisc_queue_drop(sch, &sch->q);
|
|
}
|
|
|
|
static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
|
|
{
|
|
kfree_skb(skb);
|
|
sch->qstats.drops++;
|
|
|
|
return NET_XMIT_DROP;
|
|
}
|
|
|
|
static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
|
|
{
|
|
sch->qstats.drops++;
|
|
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
|
|
goto drop;
|
|
|
|
return NET_XMIT_SUCCESS;
|
|
|
|
drop:
|
|
#endif
|
|
kfree_skb(skb);
|
|
return NET_XMIT_DROP;
|
|
}
|
|
|
|
/* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
|
|
long it will take to send a packet given its size.
|
|
*/
|
|
static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
|
|
{
|
|
int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
|
|
if (slot < 0)
|
|
slot = 0;
|
|
slot >>= rtab->rate.cell_log;
|
|
if (slot > 255)
|
|
return (rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]);
|
|
return rtab->data[slot];
|
|
}
|
|
|
|
#ifdef CONFIG_NET_CLS_ACT
|
|
static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask)
|
|
{
|
|
struct sk_buff *n = skb_clone(skb, gfp_mask);
|
|
|
|
if (n) {
|
|
n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
|
|
n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
|
|
n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
|
|
}
|
|
return n;
|
|
}
|
|
#endif
|
|
|
|
#endif
|