C++ qdisc_priv函数代码示例

static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	struct nlattr *nest;
	struct tc_tbf_qopt opt;

	sch->qstats.backlog = q->qdisc->qstats.backlog;
	nest = nla_nest_start(skb, TCA_OPTIONS);
	if (nest == NULL)
		goto nla_put_failure;

	opt.limit = q->limit;
	psched_ratecfg_getrate(&opt.rate, &q->rate);
	if (q->peak_present)
		psched_ratecfg_getrate(&opt.peakrate, &q->peak);
	else
		memset(&opt.peakrate, 0, sizeof(opt.peakrate));
	opt.mtu = PSCHED_NS2TICKS(q->mtu);
	opt.buffer = PSCHED_NS2TICKS(q->buffer);
	if (nla_put(skb, TCA_TBF_PARMS, sizeof(opt), &opt))
		goto nla_put_failure;
	if (q->rate.rate_bytes_ps >= (1ULL << 32) &&
	    nla_put_u64(skb, TCA_TBF_RATE64, q->rate.rate_bytes_ps))
		goto nla_put_failure;
	if (q->peak_present &&
	    q->peak.rate_bytes_ps >= (1ULL << 32) &&
	    nla_put_u64(skb, TCA_TBF_PRATE64, q->peak.rate_bytes_ps))
		goto nla_put_failure;

	nla_nest_end(skb, nest);
	return skb->len;

nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -1;
}

static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	unsigned char *b = skb_tail_pointer(skb);
	struct tc_sfq_qopt_v1 opt;
	struct red_parms *p = q->red_parms;

	memset(&opt, 0, sizeof(opt));
	opt.v0.quantum	= q->quantum;
	opt.v0.perturb_period = q->perturb_period / HZ;
	opt.v0.limit	= q->limit;
	opt.v0.divisor	= q->divisor;
	opt.v0.flows	= q->maxflows;
	opt.depth	= q->maxdepth;
	opt.headdrop	= q->headdrop;

	if (p) {
		opt.qth_min	= p->qth_min >> p->Wlog;
		opt.qth_max	= p->qth_max >> p->Wlog;
		opt.Wlog	= p->Wlog;
		opt.Plog	= p->Plog;
		opt.Scell_log	= p->Scell_log;
		opt.max_P	= p->max_P;
	}
	memcpy(&opt.stats, &q->stats, sizeof(opt.stats));
	opt.flags	= q->flags;

	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
		goto nla_put_failure;

	return skb->len;

nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
		      struct sk_buff **to_free)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	struct fq_flow *f;

	if (unlikely(sch->q.qlen >= sch->limit))
		return qdisc_drop(skb, sch, to_free);

	f = fq_classify(skb, q);
	if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
		q->stat_flows_plimit++;
		return qdisc_drop(skb, sch, to_free);
	}

	f->qlen++;
	if (skb_is_retransmit(skb))
		q->stat_tcp_retrans++;
	qdisc_qstats_backlog_inc(sch, skb);
	if (fq_flow_is_detached(f)) {
		fq_flow_add_tail(&q->new_flows, f);
		if (time_after(jiffies, f->age + q->flow_refill_delay))
			f->credit = max_t(u32, f->credit, q->quantum);
		q->inactive_flows--;
	}

	/* Note: this overwrites f->age */
	flow_queue_add(f, skb);

	if (unlikely(f == &q->internal)) {
		q->stat_internal_packets++;
	}
	sch->q.qlen++;

	return NET_XMIT_SUCCESS;
}

static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct fq_sched_data *q = qdisc_priv(sch);
	struct tc_fq_qd_stats st;

	sch_tree_lock(sch);

	st.gc_flows		  = q->stat_gc_flows;
	st.highprio_packets	  = q->stat_internal_packets;
	st.tcp_retrans		  = q->stat_tcp_retrans;
	st.throttled		  = q->stat_throttled;
	st.flows_plimit		  = q->stat_flows_plimit;
	st.pkts_too_long	  = q->stat_pkts_too_long;
	st.allocation_errors	  = q->stat_allocation_errors;
	st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns();
	st.flows		  = q->flows;
	st.inactive_flows	  = q->inactive_flows;
	st.throttled_flows	  = q->throttled_flows;
	st.unthrottle_latency_ns  = min_t(unsigned long,
					  q->unthrottle_latency_ns, ~0U);
	sch_tree_unlock(sch);

	return gnet_stats_copy_app(d, &st, sizeof(st));
}

static int codel_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct codel_sched_data *q = qdisc_priv(sch);

	sch->limit = DEFAULT_CODEL_LIMIT;

	codel_params_init(&q->params);
	codel_vars_init(&q->vars);
	codel_stats_init(&q->stats);

	if (opt) {
		int err = codel_change(sch, opt);

		if (err)
			return err;
	}

	if (sch->limit >= 1)
		sch->flags |= TCQ_F_CAN_BYPASS;
	else
		sch->flags &= ~TCQ_F_CAN_BYPASS;

	return 0;
}

static int tbf_enqueue(struct sk_buff *skb, struct Qdisc *sch,
		       struct sk_buff **to_free)
{
	struct tbf_sched_data *q = qdisc_priv(sch);
	unsigned int len = qdisc_pkt_len(skb);
	int ret;

	if (qdisc_pkt_len(skb) > q->max_size) {
		if (skb_is_gso(skb) &&
		    skb_gso_validate_mac_len(skb, q->max_size))
			return tbf_segment(skb, sch, to_free);
		return qdisc_drop(skb, sch, to_free);
	}
	ret = qdisc_enqueue(skb, q->qdisc, to_free);
	if (ret != NET_XMIT_SUCCESS) {
		if (net_xmit_drop_count(ret))
			qdisc_qstats_drop(sch);
		return ret;
	}

	sch->qstats.backlog += len;
	sch->q.qlen++;
	return NET_XMIT_SUCCESS;
}

static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
	struct fq_codel_sched_data *q = qdisc_priv(sch);
	struct tc_fq_codel_xstats st = {
		.type				= TCA_FQ_CODEL_XSTATS_QDISC,
	};
	struct list_head *pos;

	st.qdisc_stats.maxpacket = q->cstats.maxpacket;
	st.qdisc_stats.drop_overlimit = q->drop_overlimit;
	st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
	st.qdisc_stats.new_flow_count = q->new_flow_count;
	st.qdisc_stats.ce_mark = q->cstats.ce_mark;
	st.qdisc_stats.memory_usage  = q->memory_usage;
	st.qdisc_stats.drop_overmemory = q->drop_overmemory;

	list_for_each(pos, &q->new_flows)
		st.qdisc_stats.new_flows_len++;

	list_for_each(pos, &q->old_flows)
		st.qdisc_stats.old_flows_len++;

	return gnet_stats_copy_app(d, &st, sizeof(st));
}

static void fq_codel_reset(struct Qdisc *sch)
{
	struct fq_codel_sched_data *q = qdisc_priv(sch);
	int i;

	INIT_LIST_HEAD(&q->new_flows);
	INIT_LIST_HEAD(&q->old_flows);
	for (i = 0; i < q->flows_cnt; i++) {
		struct fq_codel_flow *flow = q->flows + i;

		while (flow->head) {
			struct sk_buff *skb = dequeue_head(flow);

			qdisc_qstats_backlog_dec(sch, skb);
			kfree_skb(skb);
		}

		INIT_LIST_HEAD(&flow->flowchain);
		codel_vars_init(&flow->cvars);
	}
	memset(q->backlogs, 0, q->flows_cnt * sizeof(u32));
	sch->q.qlen = 0;
	q->memory_usage = 0;
}

static void netem_watchdog(unsigned long arg)
{
	struct Qdisc *sch = (struct Qdisc *)arg;
	struct netem_sched_data *q = qdisc_priv(sch);
	struct net_device *dev = sch->dev;
	struct sk_buff *skb;
	psched_time_t now;

	pr_debug("netem_watchdog: fired @%lu\n", jiffies);

	spin_lock_bh(&dev->queue_lock);
	PSCHED_GET_TIME(now);

	while ((skb = skb_peek(&q->delayed)) != NULL) {
		const struct netem_skb_cb *cb
			= (const struct netem_skb_cb *)skb->cb;
		long delay 
			= PSCHED_US2JIFFIE(PSCHED_TDIFF(cb->time_to_send, now));
		pr_debug("netem_watchdog: skb %[email protected]%lu %ld\n",
			 skb, jiffies, delay);

		/* if more time remaining? */
		if (delay > 0) {
			mod_timer(&q->timer, jiffies + delay);
			break;
		}
		__skb_unlink(skb, &q->delayed);

		if (q->qdisc->enqueue(skb, q->qdisc)) {
			sch->q.qlen--;
			sch->qstats.drops++;
		}
	}
	qdisc_run(dev);
	spin_unlock_bh(&dev->queue_lock);
}

static struct sk_buff *netem_dequeue(struct Qdisc *sch)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;

	skb = q->qdisc->dequeue(q->qdisc);
	if (skb) {
		const struct netem_skb_cb *cb
			= (const struct netem_skb_cb *)skb->cb;
		psched_time_t now;

		/* if more time remaining? */
		PSCHED_GET_TIME(now);

		if (PSCHED_TLESS(cb->time_to_send, now)) {
			pr_debug("netem_dequeue: return skb=%p\n", skb);
			sch->q.qlen--;
			sch->flags &= ~TCQ_F_THROTTLED;
			return skb;
		} else {
			psched_tdiff_t delay = PSCHED_TDIFF(cb->time_to_send, now);

			if (q->qdisc->ops->requeue(skb, q->qdisc) != NET_XMIT_SUCCESS) {
				qdisc_tree_decrease_qlen(q->qdisc, 1);
				sch->qstats.drops++;
				printk(KERN_ERR "netem: queue discpline %s could not requeue\n",
				       q->qdisc->ops->id);
			}

			mod_timer(&q->timer, jiffies + PSCHED_US2JIFFIE(delay));
			sch->flags |= TCQ_F_THROTTLED;
		}
	}

	return NULL;
}

static struct sk_buff *
sfq_dequeue(struct Qdisc *sch)
{
	struct sfq_sched_data *q = qdisc_priv(sch);
	struct sk_buff *skb;
	sfq_index a, old_a;

	/* No active slots */
	if (q->tail == SFQ_DEPTH)
		return NULL;

	a = old_a = q->next[q->tail];

	/* Grab packet */
	skb = __skb_dequeue(&q->qs[a]);
	sfq_dec(q, a);
	sch->q.qlen--;
	sch->qstats.backlog -= qdisc_pkt_len(skb);

	/* Is the slot empty? */
	if (q->qs[a].qlen == 0) {
		q->ht[q->hash[a]] = SFQ_DEPTH;
		a = q->next[a];
		if (a == old_a) {
			q->tail = SFQ_DEPTH;
			return skb;
		}
		q->next[q->tail] = a;
		q->allot[a] += q->quantum;
	} else if ((q->allot[a] -= qdisc_pkt_len(skb)) <= 0) {
		q->tail = a;
		a = q->next[a];
		q->allot[a] += q->quantum;
	}
	return skb;
}

static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
			   struct netlink_ext_ack *extack)
{
	unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;
	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
	int prio;

	/* guard against zero length rings */
	if (!qlen)
		return -EINVAL;

	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
		struct skb_array *q = band2list(priv, prio);
		int err;

		err = skb_array_init(q, qlen, GFP_KERNEL);
		if (err)
			return -ENOMEM;
	}

	/* Can by-pass the queue discipline */
	qdisc->flags |= TCQ_F_CAN_BYPASS;
	return 0;
}

/* Put skb in the private delayed queue. */
static int delay_skb(struct Qdisc *sch, struct sk_buff *skb)
{
	struct netem_sched_data *q = qdisc_priv(sch);
	struct netem_skb_cb *cb = (struct netem_skb_cb *)skb->cb;
	psched_tdiff_t td;
	psched_time_t now;
	
	PSCHED_GET_TIME(now);
	td = tabledist(q->latency, q->jitter, &q->delay_cor, q->delay_dist);
	PSCHED_TADD2(now, td, cb->time_to_send);
	
	/* Always queue at tail to keep packets in order */
	if (likely(q->delayed.qlen < q->limit)) {
		__skb_queue_tail(&q->delayed, skb);
		if (!timer_pending(&q->timer)) {
			q->timer.expires = jiffies + PSCHED_US2JIFFIE(td);
			add_timer(&q->timer);
		}
		return NET_XMIT_SUCCESS;
	}

	kfree_skb(skb);
	return NET_XMIT_DROP;
}

static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{

	struct sfb_sched_data *q = qdisc_priv(sch);
	struct Qdisc *child = q->qdisc;
	int i;
	u32 p_min = ~0;
	u32 minqlen = ~0;
	u32 r, slot, salt, sfbhash;
	int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
	struct flow_keys keys;

	if (unlikely(sch->q.qlen >= q->limit)) {
		sch->qstats.overlimits++;
		q->stats.queuedrop++;
		goto drop;
	}

	if (q->rehash_interval > 0) {
		unsigned long limit = q->rehash_time + q->rehash_interval;

		if (unlikely(time_after(jiffies, limit))) {
			sfb_swap_slot(q);
			q->rehash_time = jiffies;
		} else if (unlikely(!q->double_buffering && q->warmup_time > 0 &&
				    time_after(jiffies, limit - q->warmup_time))) {
			q->double_buffering = true;
		}
	}

	if (q->filter_list) {
		/* If using external classifiers, get result and record it. */
		if (!sfb_classify(skb, q, &ret, &salt))
			goto other_drop;
		keys.src = salt;
		keys.dst = 0;
		keys.ports = 0;
	} else {
		skb_flow_dissect(skb, &keys);
	}

	slot = q->slot;

	sfbhash = jhash_3words((__force u32)keys.dst,
			       (__force u32)keys.src,
			       (__force u32)keys.ports,
			       q->bins[slot].perturbation);
	if (!sfbhash)
		sfbhash = 1;
	sfb_skb_cb(skb)->hashes[slot] = sfbhash;

	for (i = 0; i < SFB_LEVELS; i++) {
		u32 hash = sfbhash & SFB_BUCKET_MASK;
		struct sfb_bucket *b = &q->bins[slot].bins[i][hash];

		sfbhash >>= SFB_BUCKET_SHIFT;
		if (b->qlen == 0)
			decrement_prob(b, q);
		else if (b->qlen >= q->bin_size)
			increment_prob(b, q);
		if (minqlen > b->qlen)
			minqlen = b->qlen;
		if (p_min > b->p_mark)
			p_min = b->p_mark;
	}

	slot ^= 1;
	sfb_skb_cb(skb)->hashes[slot] = 0;

	if (unlikely(minqlen >= q->max)) {
		sch->qstats.overlimits++;
		q->stats.bucketdrop++;
		goto drop;
	}

	if (unlikely(p_min >= SFB_MAX_PROB)) {
		/* Inelastic flow */
		if (q->double_buffering) {
			sfbhash = jhash_3words((__force u32)keys.dst,
					       (__force u32)keys.src,
					       (__force u32)keys.ports,
					       q->bins[slot].perturbation);
			if (!sfbhash)
				sfbhash = 1;
			sfb_skb_cb(skb)->hashes[slot] = sfbhash;

			for (i = 0; i < SFB_LEVELS; i++) {
				u32 hash = sfbhash & SFB_BUCKET_MASK;
				struct sfb_bucket *b = &q->bins[slot].bins[i][hash];

				sfbhash >>= SFB_BUCKET_SHIFT;
				if (b->qlen == 0)
					decrement_prob(b, q);
				else if (b->qlen >= q->bin_size)
					increment_prob(b, q);
			}
		}
		if (sfb_rate_limit(skb, q)) {
			sch->qstats.overlimits++;
			q->stats.penaltydrop++;
//.........这里部分代码省略.........

static inline struct sk_buff_head *prio2list(struct sk_buff *skb,
					     struct Qdisc *qdisc)
{
	struct sk_buff_head *list = qdisc_priv(qdisc);
	return list + prio2band[skb->priority & TC_PRIO_MAX];
}