// SPDX-License-Identifier: GPL-2.0-only

  /* net/sched/sch_atm.c - ATM VC selection "queueing discipline" */
  
  /* Written 1998-2000 by Werner Almesberger, EPFL ICA */

  #include <linux/module.h>

  #include <linux/slab.h>

  #include <linux/init.h>

  #include <linux/interrupt.h>

  #include <linux/string.h>
  #include <linux/errno.h>
  #include <linux/skbuff.h>

  #include <linux/atmdev.h>
  #include <linux/atmclip.h>

  #include <linux/rtnetlink.h>

  #include <linux/file.h>		/* for fput */

  #include <net/netlink.h>

  #include <net/pkt_sched.h>

  #include <net/pkt_cls.h>

  /*
   * The ATM queuing discipline provides a framework for invoking classifiers
   * (aka "filters"), which in turn select classes of this queuing discipline.
   * Each class maps the flow(s) it is handling to a given VC. Multiple classes
   * may share the same VC.
   *
   * When creating a class, VCs are specified by passing the number of the open
   * socket descriptor by which the calling process references the VC. The kernel
   * keeps the VC open at least until all classes using it are removed.
   *
   * In this file, most functions are named atm_tc_* to avoid confusion with all
   * the atm_* in net/atm. This naming convention differs from what's used in the
   * rest of net/sched.
   *
   * Known bugs:
   *  - sometimes messes up the IP stack
   *  - any manipulations besides the few operations described in the README, are
   *    untested and likely to crash the system
   *  - should lock the flow while there is data in the queue (?)
   */

  #define VCC2FLOW(vcc) ((struct atm_flow_data *) ((vcc)->user_back))

  struct atm_flow_data {

  	struct Qdisc_class_common common;

  	struct Qdisc		*q;	/* FIFO, TBF, etc. */

  	struct tcf_proto __rcu	*filter_list;

  	struct tcf_block	*block;

  	struct atm_vcc		*vcc;	/* VCC; NULL if VCC is closed */
  	void			(*old_pop)(struct atm_vcc *vcc,

  					   struct sk_buff *skb); /* chaining */

  	struct atm_qdisc_data	*parent;	/* parent qdisc */
  	struct socket		*sock;		/* for closing */

  	int			ref;		/* reference count */

  	struct gnet_stats_basic_packed	bstats;

  	struct gnet_stats_queue	qstats;

  	struct list_head	list;

  	struct atm_flow_data	*excess;	/* flow for excess traffic;
  						   NULL to set CLP instead */
  	int			hdr_len;

  	unsigned char		hdr[];		/* header data; MUST BE LAST */

  };
  
  struct atm_qdisc_data {
  	struct atm_flow_data	link;		/* unclassified skbs go here */

  	struct list_head	flows;		/* NB: "link" is also on this

  						   list */

  	struct tasklet_struct	task;		/* dequeue tasklet */

  };

  /* ------------------------- Class/flow operations ------------------------- */

  static inline struct atm_flow_data *lookup_flow(struct Qdisc *sch, u32 classid)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow;

  	list_for_each_entry(flow, &p->flows, list) {

  		if (flow->common.classid == classid)

  			return flow;
  	}
  	return NULL;

  }

  static int atm_tc_graft(struct Qdisc *sch, unsigned long arg,

  			struct Qdisc *new, struct Qdisc **old,
  			struct netlink_ext_ack *extack)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)arg;

  	pr_debug("atm_tc_graft(sch %p,[qdisc %p],flow %p,new %p,old %p)
  ",

  		sch, p, flow, new, old);

  	if (list_empty(&flow->list))

  		return -EINVAL;
  	if (!new)
  		new = &noop_qdisc;

  	*old = flow->q;
  	flow->q = new;

  	if (*old)
  		qdisc_reset(*old);

  	return 0;

  }

  static struct Qdisc *atm_tc_leaf(struct Qdisc *sch, unsigned long cl)

  {

  	struct atm_flow_data *flow = (struct atm_flow_data *)cl;

  	pr_debug("atm_tc_leaf(sch %p,flow %p)
  ", sch, flow);

  	return flow ? flow->q : NULL;
  }

  static unsigned long atm_tc_find(struct Qdisc *sch, u32 classid)

  {

  	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);

  	struct atm_flow_data *flow;

  	pr_debug("%s(sch %p,[qdisc %p],classid %x)
  ", __func__, sch, p, classid);

  	flow = lookup_flow(sch, classid);

  	pr_debug("%s: flow %p
  ", __func__, flow);

  	return (unsigned long)flow;

  }

  static unsigned long atm_tc_bind_filter(struct Qdisc *sch,

  					unsigned long parent, u32 classid)

  {

  	struct atm_qdisc_data *p __maybe_unused = qdisc_priv(sch);
  	struct atm_flow_data *flow;
  
  	pr_debug("%s(sch %p,[qdisc %p],classid %x)
  ", __func__, sch, p, classid);
  	flow = lookup_flow(sch, classid);
  	if (flow)
  		flow->ref++;
  	pr_debug("%s: flow %p
  ", __func__, flow);
  	return (unsigned long)flow;

  }

  /*
   * atm_tc_put handles all destructions, including the ones that are explicitly
   * requested (atm_tc_destroy, etc.). The assumption here is that we never drop
   * anything that still seems to be in use.
   */

  static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)cl;

  	pr_debug("atm_tc_put(sch %p,[qdisc %p],flow %p)
  ", sch, p, flow);

  	if (--flow->ref)
  		return;

  	pr_debug("atm_tc_put: destroying
  ");

  	list_del_init(&flow->list);

  	pr_debug("atm_tc_put: qdisc %p
  ", flow->q);

  	qdisc_put(flow->q);

  	tcf_block_put(flow->block);

  	if (flow->sock) {

  		pr_debug("atm_tc_put: f_count %ld
  ",

  			file_count(flow->sock->file));

  		flow->vcc->pop = flow->old_pop;
  		sockfd_put(flow->sock);
  	}

  	if (flow->excess)
  		atm_tc_put(sch, (unsigned long)flow->excess);
  	if (flow != &p->link)
  		kfree(flow);

  	/*
  	 * If flow == &p->link, the qdisc no longer works at this point and
  	 * needs to be removed. (By the caller of atm_tc_put.)
  	 */
  }

  static void sch_atm_pop(struct atm_vcc *vcc, struct sk_buff *skb)

  {
  	struct atm_qdisc_data *p = VCC2FLOW(vcc)->parent;

  	pr_debug("sch_atm_pop(vcc %p,skb %p,[qdisc %p])
  ", vcc, skb, p);

  	VCC2FLOW(vcc)->old_pop(vcc, skb);

  	tasklet_schedule(&p->task);
  }
  
  static const u8 llc_oui_ip[] = {

  	0xaa,			/* DSAP: non-ISO */
  	0xaa,			/* SSAP: non-ISO */
  	0x03,			/* Ctrl: Unnumbered Information Command PDU */
  	0x00,			/* OUI: EtherType */

  	0x00, 0x00,

  	0x08, 0x00
  };				/* Ethertype IP (0800) */

  static const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = {
  	[TCA_ATM_FD]		= { .type = NLA_U32 },
  	[TCA_ATM_EXCESS]	= { .type = NLA_U32 },
  };

  static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,

  			 struct nlattr **tca, unsigned long *arg,
  			 struct netlink_ext_ack *extack)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)*arg;

  	struct atm_flow_data *excess = NULL;

  	struct nlattr *opt = tca[TCA_OPTIONS];
  	struct nlattr *tb[TCA_ATM_MAX + 1];

  	struct socket *sock;

  	int fd, error, hdr_len;

  	void *hdr;

  	pr_debug("atm_tc_change(sch %p,[qdisc %p],classid %x,parent %x,"

  		"flow %p,opt %p)
  ", sch, p, classid, parent, flow, opt);

  	/*
  	 * The concept of parents doesn't apply for this qdisc.
  	 */
  	if (parent && parent != TC_H_ROOT && parent != sch->handle)
  		return -EINVAL;
  	/*
  	 * ATM classes cannot be changed. In order to change properties of the
  	 * ATM connection, that socket needs to be modified directly (via the
  	 * native ATM API. In order to send a flow to a different VC, the old
  	 * class needs to be removed and a new one added. (This may be changed
  	 * later.)
  	 */

  	if (flow)
  		return -EBUSY;

  	if (opt == NULL)

  		return -EINVAL;

  	error = nla_parse_nested_deprecated(tb, TCA_ATM_MAX, opt, atm_policy,
  					    NULL);

  	if (error < 0)
  		return error;

  	if (!tb[TCA_ATM_FD])

  		return -EINVAL;

  	fd = nla_get_u32(tb[TCA_ATM_FD]);

  	pr_debug("atm_tc_change: fd %d
  ", fd);

  	if (tb[TCA_ATM_HDR]) {
  		hdr_len = nla_len(tb[TCA_ATM_HDR]);
  		hdr = nla_data(tb[TCA_ATM_HDR]);

  	} else {

  		hdr_len = RFC1483LLC_LEN;

  		hdr = NULL;	/* default LLC/SNAP for IP */

  	}

  	if (!tb[TCA_ATM_EXCESS])

  		excess = NULL;

  	else {

  		excess = (struct atm_flow_data *)

  			atm_tc_find(sch, nla_get_u32(tb[TCA_ATM_EXCESS]));

  		if (!excess)
  			return -ENOENT;

  	}

  	pr_debug("atm_tc_change: type %d, payload %d, hdr_len %d
  ",

  		 opt->nla_type, nla_len(opt), hdr_len);

  	sock = sockfd_lookup(fd, &error);
  	if (!sock)

  		return error;	/* f_count++ */

  	pr_debug("atm_tc_change: f_count %ld
  ", file_count(sock->file));

  	if (sock->ops->family != PF_ATMSVC && sock->ops->family != PF_ATMPVC) {

  		error = -EPROTOTYPE;

  		goto err_out;

  	}
  	/* @@@ should check if the socket is really operational or we'll crash
  	   on vcc->send */
  	if (classid) {
  		if (TC_H_MAJ(classid ^ sch->handle)) {

  			pr_debug("atm_tc_change: classid mismatch
  ");

  			error = -EINVAL;
  			goto err_out;
  		}

  	} else {

  		int i;
  		unsigned long cl;
  
  		for (i = 1; i < 0x8000; i++) {

  			classid = TC_H_MAKE(sch->handle, 0x8000 | i);

  			cl = atm_tc_find(sch, classid);

  			if (!cl)

  				break;

  		}
  	}

  	pr_debug("atm_tc_change: new id %x
  ", classid);

  	flow = kzalloc(sizeof(struct atm_flow_data) + hdr_len, GFP_KERNEL);

  	pr_debug("atm_tc_change: flow %p
  ", flow);

  	if (!flow) {
  		error = -ENOBUFS;
  		goto err_out;
  	}

  	error = tcf_block_get(&flow->block, &flow->filter_list, sch,
  			      extack);

  	if (error) {
  		kfree(flow);
  		goto err_out;
  	}

  	flow->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid,
  				    extack);

  	if (!flow->q)

  		flow->q = &noop_qdisc;

  	pr_debug("atm_tc_change: qdisc %p
  ", flow->q);

  	flow->sock = sock;

  	flow->vcc = ATM_SD(sock);	/* speedup */

  	flow->vcc->user_back = flow;

  	pr_debug("atm_tc_change: vcc %p
  ", flow->vcc);

  	flow->old_pop = flow->vcc->pop;
  	flow->parent = p;
  	flow->vcc->pop = sch_atm_pop;

  	flow->common.classid = classid;

  	flow->ref = 1;
  	flow->excess = excess;

  	list_add(&flow->list, &p->link.list);

  	flow->hdr_len = hdr_len;
  	if (hdr)

  		memcpy(flow->hdr, hdr, hdr_len);

  	else

  		memcpy(flow->hdr, llc_oui_ip, sizeof(llc_oui_ip));
  	*arg = (unsigned long)flow;

  	return 0;
  err_out:

  	sockfd_put(sock);
  	return error;
  }

  static int atm_tc_delete(struct Qdisc *sch, unsigned long arg)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)arg;

  	pr_debug("atm_tc_delete(sch %p,[qdisc %p],flow %p)
  ", sch, p, flow);

  	if (list_empty(&flow->list))

  		return -EINVAL;

  	if (rcu_access_pointer(flow->filter_list) || flow == &p->link)

  		return -EBUSY;

  	/*
  	 * Reference count must be 2: one for "keepalive" (set at class
  	 * creation), and one for the reference held when calling delete.
  	 */
  	if (flow->ref < 2) {

  		pr_err("atm_tc_delete: flow->ref == %d
  ", flow->ref);

  		return -EINVAL;
  	}

  	if (flow->ref > 2)
  		return -EBUSY;	/* catch references via excess, etc. */
  	atm_tc_put(sch, arg);

  	return 0;
  }

  static void atm_tc_walk(struct Qdisc *sch, struct qdisc_walker *walker)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow;

  	pr_debug("atm_tc_walk(sch %p,[qdisc %p],walker %p)
  ", sch, p, walker);

  	if (walker->stop)
  		return;

  	list_for_each_entry(flow, &p->flows, list) {
  		if (walker->count >= walker->skip &&
  		    walker->fn(sch, (unsigned long)flow, walker) < 0) {
  			walker->stop = 1;
  			break;
  		}

  		walker->count++;
  	}
  }

  static struct tcf_block *atm_tc_tcf_block(struct Qdisc *sch, unsigned long cl,
  					  struct netlink_ext_ack *extack)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)cl;

  	pr_debug("atm_tc_find_tcf(sch %p,[qdisc %p],flow %p)
  ", sch, p, flow);

  	return flow ? flow->block : p->link.block;

  }

  /* --------------------------- Qdisc operations ---------------------------- */

  static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
  			  struct sk_buff **to_free)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow;

  	struct tcf_result res;
  	int result;

  	int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;

  	pr_debug("atm_tc_enqueue(skb %p,sch %p,[qdisc %p])
  ", skb, sch, p);

  	result = TC_ACT_OK;	/* be nice to gcc */

  	flow = NULL;

  	if (TC_H_MAJ(skb->priority) != sch->handle ||

  	    !(flow = (struct atm_flow_data *)atm_tc_find(sch, skb->priority))) {

  		struct tcf_proto *fl;

  		list_for_each_entry(flow, &p->flows, list) {

  			fl = rcu_dereference_bh(flow->filter_list);
  			if (fl) {

  				result = tcf_classify(skb, fl, &res, true);

  				if (result < 0)
  					continue;
  				flow = (struct atm_flow_data *)res.class;
  				if (!flow)
  					flow = lookup_flow(sch, res.classid);

  				goto done;

  			}

  		}
  		flow = NULL;

  done:
  		;

  	}

  	if (!flow) {

  		flow = &p->link;

  	} else {

  		if (flow->vcc)
  			ATM_SKB(skb)->atm_options = flow->vcc->atm_options;

  		/*@@@ looks good ... but it's not supposed to work :-) */

  #ifdef CONFIG_NET_CLS_ACT
  		switch (result) {
  		case TC_ACT_QUEUED:
  		case TC_ACT_STOLEN:

  		case TC_ACT_TRAP:

  			__qdisc_drop(skb, to_free);

  			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;

  		case TC_ACT_SHOT:

  			__qdisc_drop(skb, to_free);

  			goto drop;

  		case TC_ACT_RECLASSIFY:

  			if (flow->excess)
  				flow = flow->excess;
  			else
  				ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
  			break;

  		}

  #endif
  	}

  	ret = qdisc_enqueue(skb, flow->q, to_free);

  	if (ret != NET_XMIT_SUCCESS) {

  drop: __maybe_unused

  		if (net_xmit_drop_count(ret)) {

  			qdisc_qstats_drop(sch);

  			if (flow)
  				flow->qstats.drops++;
  		}

  		return ret;
  	}

  	/*
  	 * Okay, this may seem weird. We pretend we've dropped the packet if
  	 * it goes via ATM. The reason for this is that the outer qdisc
  	 * expects to be able to q->dequeue the packet later on if we return
  	 * success at this place. Also, sch->q.qdisc needs to reflect whether
  	 * there is a packet egligible for dequeuing or not. Note that the
  	 * statistics of the outer qdisc are necessarily wrong because of all
  	 * this. There's currently no correct solution for this.
  	 */
  	if (flow == &p->link) {
  		sch->q.qlen++;

  		return NET_XMIT_SUCCESS;

  	}
  	tasklet_schedule(&p->task);

  	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;

  }

  /*
   * Dequeue packets and send them over ATM. Note that we quite deliberately
   * avoid checking net_device's flow control here, simply because sch_atm
   * uses its own channels, which have nothing to do with any CLIP/LANE/or
   * non-ATM interfaces.
   */

  static void sch_atm_dequeue(unsigned long data)
  {

  	struct Qdisc *sch = (struct Qdisc *)data;

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow;
  	struct sk_buff *skb;

  	pr_debug("sch_atm_dequeue(sch %p,[qdisc %p])
  ", sch, p);

  	list_for_each_entry(flow, &p->flows, list) {
  		if (flow == &p->link)
  			continue;

  		/*
  		 * If traffic is properly shaped, this won't generate nasty
  		 * little bursts. Otherwise, it may ... (but that's okay)
  		 */

  		while ((skb = flow->q->ops->peek(flow->q))) {
  			if (!atm_may_send(flow->vcc, skb->truesize))

  				break;

  			skb = qdisc_dequeue_peeked(flow->q);

  			if (unlikely(!skb))
  				break;

  			qdisc_bstats_update(sch, skb);
  			bstats_update(&flow->bstats, skb);

  			pr_debug("atm_tc_dequeue: sending on class %p
  ", flow);

  			/* remove any LL header somebody else has attached */

  			skb_pull(skb, skb_network_offset(skb));

  			if (skb_headroom(skb) < flow->hdr_len) {
  				struct sk_buff *new;

  				new = skb_realloc_headroom(skb, flow->hdr_len);

  				dev_kfree_skb(skb);

  				if (!new)
  					continue;

  				skb = new;
  			}

  			pr_debug("sch_atm_dequeue: ip %p, data %p
  ",

  				 skb_network_header(skb), skb->data);

  			ATM_SKB(skb)->vcc = flow->vcc;

  			memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
  			       flow->hdr_len);

  			refcount_add(skb->truesize,

  				   &sk_atm(flow->vcc)->sk_wmem_alloc);
  			/* atm.atm_options are already set by atm_tc_enqueue */

  			flow->vcc->send(flow->vcc, skb);

  		}

  	}

  }

  static struct sk_buff *atm_tc_dequeue(struct Qdisc *sch)
  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct sk_buff *skb;

  	pr_debug("atm_tc_dequeue(sch %p,[qdisc %p])
  ", sch, p);

  	tasklet_schedule(&p->task);

  	skb = qdisc_dequeue_peeked(p->link.q);

  	if (skb)
  		sch->q.qlen--;

  	return skb;
  }

  static struct sk_buff *atm_tc_peek(struct Qdisc *sch)
  {
  	struct atm_qdisc_data *p = qdisc_priv(sch);
  
  	pr_debug("atm_tc_peek(sch %p,[qdisc %p])
  ", sch, p);
  
  	return p->link.q->ops->peek(p->link.q);
  }

  static int atm_tc_init(struct Qdisc *sch, struct nlattr *opt,
  		       struct netlink_ext_ack *extack)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	int err;

  	pr_debug("atm_tc_init(sch %p,[qdisc %p],opt %p)
  ", sch, p, opt);

  	INIT_LIST_HEAD(&p->flows);
  	INIT_LIST_HEAD(&p->link.list);
  	list_add(&p->link.list, &p->flows);

  	p->link.q = qdisc_create_dflt(sch->dev_queue,

  				      &pfifo_qdisc_ops, sch->handle, extack);

  	if (!p->link.q)

  		p->link.q = &noop_qdisc;

  	pr_debug("atm_tc_init: link (%p) qdisc %p
  ", &p->link, p->link.q);

  	p->link.vcc = NULL;
  	p->link.sock = NULL;
  	p->link.common.classid = sch->handle;
  	p->link.ref = 1;

  	err = tcf_block_get(&p->link.block, &p->link.filter_list, sch,
  			    extack);

  	if (err)
  		return err;

  	tasklet_init(&p->task, sch_atm_dequeue, (unsigned long)sch);

  	return 0;
  }

  static void atm_tc_reset(struct Qdisc *sch)
  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow;

  	pr_debug("atm_tc_reset(sch %p,[qdisc %p])
  ", sch, p);

  	list_for_each_entry(flow, &p->flows, list)

  		qdisc_reset(flow->q);

  	sch->q.qlen = 0;
  }

  static void atm_tc_destroy(struct Qdisc *sch)
  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow, *tmp;

  	pr_debug("atm_tc_destroy(sch %p,[qdisc %p])
  ", sch, p);

  	list_for_each_entry(flow, &p->flows, list) {

  		tcf_block_put(flow->block);

  		flow->block = NULL;
  	}

  	list_for_each_entry_safe(flow, tmp, &p->flows, list) {

  		if (flow->ref > 1)

  			pr_err("atm_destroy: %p->ref = %d
  ", flow, flow->ref);

  		atm_tc_put(sch, (unsigned long)flow);

  	}
  	tasklet_kill(&p->task);
  }

  static int atm_tc_dump_class(struct Qdisc *sch, unsigned long cl,

  			     struct sk_buff *skb, struct tcmsg *tcm)

  {

  	struct atm_qdisc_data *p = qdisc_priv(sch);

  	struct atm_flow_data *flow = (struct atm_flow_data *)cl;

  	struct nlattr *nest;

  	pr_debug("atm_tc_dump_class(sch %p,[qdisc %p],flow %p,skb %p,tcm %p)
  ",

  		sch, p, flow, skb, tcm);

  	if (list_empty(&flow->list))

  		return -EINVAL;

  	tcm->tcm_handle = flow->common.classid;

  	tcm->tcm_info = flow->q->handle;

  	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);

  	if (nest == NULL)
  		goto nla_put_failure;

  	if (nla_put(skb, TCA_ATM_HDR, flow->hdr_len, flow->hdr))
  		goto nla_put_failure;

  	if (flow->vcc) {
  		struct sockaddr_atmpvc pvc;
  		int state;

  		memset(&pvc, 0, sizeof(pvc));

  		pvc.sap_family = AF_ATMPVC;
  		pvc.sap_addr.itf = flow->vcc->dev ? flow->vcc->dev->number : -1;
  		pvc.sap_addr.vpi = flow->vcc->vpi;
  		pvc.sap_addr.vci = flow->vcc->vci;

  		if (nla_put(skb, TCA_ATM_ADDR, sizeof(pvc), &pvc))
  			goto nla_put_failure;

  		state = ATM_VF2VS(flow->vcc->flags);

  		if (nla_put_u32(skb, TCA_ATM_STATE, state))
  			goto nla_put_failure;
  	}
  	if (flow->excess) {

  		if (nla_put_u32(skb, TCA_ATM_EXCESS, flow->common.classid))

  			goto nla_put_failure;
  	} else {
  		if (nla_put_u32(skb, TCA_ATM_EXCESS, 0))
  			goto nla_put_failure;

  	}

  	return nla_nest_end(skb, nest);

  nla_put_failure:

  	nla_nest_cancel(skb, nest);

  	return -1;
  }
  static int
  atm_tc_dump_class_stats(struct Qdisc *sch, unsigned long arg,

  			struct gnet_dump *d)

  {

  	struct atm_flow_data *flow = (struct atm_flow_data *)arg;

  	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch),
  				  d, NULL, &flow->bstats) < 0 ||

  	    gnet_stats_copy_queue(d, NULL, &flow->qstats, flow->q->q.qlen) < 0)

  		return -1;
  
  	return 0;
  }
  
  static int atm_tc_dump(struct Qdisc *sch, struct sk_buff *skb)
  {
  	return 0;
  }

  static const struct Qdisc_class_ops atm_class_ops = {

  	.graft		= atm_tc_graft,
  	.leaf		= atm_tc_leaf,

  	.find		= atm_tc_find,

  	.change		= atm_tc_change,
  	.delete		= atm_tc_delete,
  	.walk		= atm_tc_walk,

  	.tcf_block	= atm_tc_tcf_block,

  	.bind_tcf	= atm_tc_bind_filter,
  	.unbind_tcf	= atm_tc_put,
  	.dump		= atm_tc_dump_class,
  	.dump_stats	= atm_tc_dump_class_stats,

  };

  static struct Qdisc_ops atm_qdisc_ops __read_mostly = {

  	.cl_ops		= &atm_class_ops,
  	.id		= "atm",
  	.priv_size	= sizeof(struct atm_qdisc_data),
  	.enqueue	= atm_tc_enqueue,
  	.dequeue	= atm_tc_dequeue,

  	.peek		= atm_tc_peek,

  	.init		= atm_tc_init,
  	.reset		= atm_tc_reset,
  	.destroy	= atm_tc_destroy,
  	.dump		= atm_tc_dump,
  	.owner		= THIS_MODULE,

  };

  static int __init atm_init(void)
  {
  	return register_qdisc(&atm_qdisc_ops);
  }

  static void __exit atm_exit(void)

  {
  	unregister_qdisc(&atm_qdisc_ops);
  }
  
  module_init(atm_init)
  module_exit(atm_exit)
  MODULE_LICENSE("GPL");